Fuel injection nozzle

ABSTRACT

In a fuel injection nozzle that has an intermediate plate extending normal to the nozzle axis and serving in particular as an abutment for limiting the stroke of the valve needle, the aligning pins passing through separate openings in said intermediate plate are disposed in mirror symmetry with respect to a plane containing the nozzle axis. The plane defined by the pin axes is spaced from the nozzle axis. The fuel supply channel or channels which extend within the fuel injection nozzle and which pass through openings in the plate are also in mirror symmetry with respect to the first-named plane.

ilnited States Patent 1191 Kinzel et al.

[ Dec. 11, 1973 FUEL INJECTION NO ZZLE [73] Assignee: Robert Bosch Gmbll, Stuttgart,

Germany [22] Filed: Mar. 31, 1972 [2]] Appl. No.: 239,929

[30] Foreign Application Priority Data Apr. 23, 1971 Germany P 21 19 973.5

[52] US. Cl. 239/533 [51] Int. Cl B05b 1/32 [58] Field of Search 239/ 88, 453, 533

[56] References Cited UNITED STATES PATENTS 3,567,133 3/1971 Gewinner 239/533 3,460,760 8/1969 Bluhm 239/533 X FOREIGN PATENTS OR APPLICATIONS 504,988 5/1939 Great Britain 239/533 1,907,340 8/1970 Germany 239/533 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Michael Y. Mar Attorney-Edwin E. Greigg [57] ABSTRACT In a fuel injection nozzle that has an intermediate plate extending normal to the nozzle axis and serving in particular as an abutment for limiting the stroke of the valve needle, the aligning pins passing through separate openings in said intermediate plate are disposed in mirror symmetry with respect to a plane containing the nozzle axis. The plane defined by the pin axes is spaced from the nozzle axis. The fuel supply channel or channels which extend within the fuel injection nozzle and which pass through openings in the plate are also in mirror symmetry with respect to the first-named plane.

5 Claims, 3 Drawing Figures FUEL INJECTION NOZZLE THE INVENTION This invention relates to a fuel injection nozzle of the type that is provided with an intermediate plate clamped between the nozzle body and the nozzle holder and oriented by two aligning pins extending through the last-named two components. The particular function of the intermediate plate is to serve as an abutment for the valve needle and thus limit its stroke. The nozzle structure is further provided with at least one fuel supply bore passing through the aforenoted intermediate plate.

In internal combustion engines operating on injected fuel the injection nozzle has to be removed often and disassembled for cleaning or for replacing certain components, such as the nozzle body including the valve needle. During such operation, it is a common occurrence that the aforenoted intermediate plate is inserted the wrong way during reassembly, so that'the fuel supply bore will be blocked and thus when attempt is made to operate the engine, the nozzle will not function; it may even suffer damage as a result.

SUMMARY OF THE INVENTION It is an object of the invention to provide a fuel injection nozzle in which an unintentional blocking of the fuel supply channel by an incorrect insertion of the intermediate plate is not possible.

Briefly stated, according to the invention, the aligning pins are arranged in mirror symmetry with respect to a plane containing the nozzle axis. The fuel supply bore or bores are also arranged in mirror symmetry relative to this plane. The plane defined by the pin axes and the plane containing the fuel bore axes extend parallel to one another and are both spaced from the nozzle axis.

When the aligning pins and the supply bores are arranged in the aforeoutlined manner, the intermediate plate may be turned around if the stroke of the valve needle renders this necessary.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood, as well as further objects and advantages become more apparent, from the ensuing specification of several exemplary embodiments taken in conjunction with the drawing, wherein:

FIG. 1 is an axial sectional view of a first embodiment of the fuel injection nozzle according to the invention;

FIG. 2 is a plan view of an intermediate plate forming one component of the structure illustrated in FIG. 1 and FIG. 3 is a plan view of a modified intermediate plate adapted to be used in a second embodiment of the fuel injection nozzle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to the figures, a nozzle body 1 is tightened to a nozzle holder 3 by means of a sleeve nut 2. Between the nozzle body 1 and the nozzle holder 3 there is disposed an intermediate plate 4 which serves in particular as an abutment to limit the stroke of a valve needle 5.

The nozzle body 1, the nozzle holder 3 and the intermediate plate 4 are immobilized in a certain angular relationship with respect to one another by means of two aligning pins 6 (only oneseen in FIG. 1) extending through openings 6a (FIG. 2) provided in the intermediate plate 4. From the fuel injection pump (not shown) fuel is admitted to the fuel injection nozzle through a fuel supply channel 7 which merges in a pressure chamber 8 situated in the nozzle body 1. The continuity of the fuel supply channel 7 is ensured by an opening 7a provided in the intermediate plate 4. As it may be observed from FIGS. 2 and 3, in FIG. 1 the pin 6 and the channel 7 are, for the sake of clarity, rotated approximately with respect to the nozzle axis. The intermediate plate 4 also has a central opening 5a through which a stem portion of the valve needle 5 passes.

The intermediate plate 4' illustrated in FIG. 3 differs from the intermediate plate 4 of FIGS. 1 and 2 only in that it has two openings 7b. Such an intermediate plate is used in a fuel injection nozzle having two fuel supply bores.

1 With particular reference to FIGS. 2 and 3, the axes lof the two aligning pins 6 (and thus the center of each jopening 6a) are disposed in a plane X1 which extends inormal to a plane Z containing the nozzle axis Y. The aligning pins 6 are thus arranged in mirror symmetry with respect to the plane Z. Further, the plane X1 has ino common point or points with the nozzle axis Y. What was said of plane XI also applies in the embodii'n'ent of FIG. 3 to a plane X2 which extends parallel iwith the plane X1 and in which lie the axes of the fuel channel openings 7b. In the embodiment of FIG. 2, the benter of the opening 7a lies directly in the plane Z; consequently, in this case, as in the embodiment acbording to FIG. 3, the fuel supply channels, or, more precisely, the opening therefor in the intermediate plate 4, are in mirror symmetry with respect to the plane Z. L In the aforedescribed arrangement, it is immaterial how the intermediate plate 4 is inserted; in each case, as long as the aligning pins can both be inserted into heir associated openings 6a provided in the intermediate plate, a throughgoing passage of the fuel supply channel or channels 7 is ensured.

That which is claimed is:

1. In a fuel injection nozzle of the known type that has (a) a nozzle body, (b) a valve needle reciprocably held in said nozzle body, (c) a nozzle holder tightened to said nozzle body, (d) at least one fuel supply channel extending longitudinally in said nozzle holder and said nozzle body, (e) an intermediate plate extending substantially normal to the longitudinal axis of said fuel injection nozzle, said intermediate plate having a separate opening aligned with each fuel supply channel, said intermediate plate serving in particular as an abutment for said valve needle to limit the stroke thereof and (f) at least two aligning pins each disposed partially in said nozzle body in said nozzle holder and in further separate openings provided in said intermediate plate, the improvement comprising the arrangement of said aligning pins and said at least one fuel supply channel at the location of said intermediate plate, wherein said aligning pins are in mirror symmetry with respect to a plane containing the longitudinal axis of said fuel injection nozzle and the axes of said aligning pins define a plane that is spaced from said nozzle axis, said at least one fuel supply channel is positioned in mirror symmesaid two fuel supply channels are disposed in mirror symmetry with respect to said plane containing said nozzle axis on one and on the other side thereof, the axes of said two fuel supply channels define a plane extending parallel to the plane defined by the pin axes.

5. An arrangement as defined in claim 4, wherein said plane defined by the axes of said two fuel supply channels is spaced from said nozzle axis. 

1. In a fuel injection nozzle of the known type that has (a) a nozzle body, (b) a valve needle reciprocably held in said nozzle body, (c) a nozzle holder tightened to said nozzle body, (d) at least one fuel supply channel extending longitudinally in said nozzle holder and said nozzle body, (e) an intermediate plate extending substantially normal to the longitudinal axis of said fuel injection nozzle, said intermediate plate having a separate opening aligned with each fuel supply channel, said intermediate plate serving in particular as an abutment for said valve needle to limit the stroke thereof and (f) at least two aligning pins each disposed partially in said nozzle body in said nozzle holder and in further separate openings provided in said intermediate plate, the improvement comprising the arrangement of said aligning pins and said at least one fuel supply channel at the location of said intermediate plate, wherein said aligning pins are in mirror symmetry with respect to a plane containing the longitudinal axis of said fuel injection nozzle and the axes of said aligning pins define a plane that is spaced from said nozzle axis, said at least one fuel supply channel is positioned in mirror symmetry with respect to said plane containing said nozzle axis.
 2. An arrangement as defined in claim 1, wherein the number of said at least one fuel supply channel is one, said one fuel supply channel is, at said intermediate plate, symmetrically situated with respect to said plane containing said nozzle axis.
 3. An arrangement as defined in claim 1, wherein the number of said at least one fuel supply channel is two.
 4. An arrangement as defined in claIm 3, wherein said two fuel supply channels are disposed in mirror symmetry with respect to said plane containing said nozzle axis on one and on the other side thereof, the axes of said two fuel supply channels define a plane extending parallel to the plane defined by the pin axes.
 5. An arrangement as defined in claim 4, wherein said plane defined by the axes of said two fuel supply channels is spaced from said nozzle axis. 